scholarly journals Metabolic connectivity for differential diagnosis of dementing disorders

2016 ◽  
Vol 37 (1) ◽  
pp. 252-262 ◽  
Author(s):  
Dmitry Titov ◽  
Janine Diehl-Schmid ◽  
Kuangyu Shi ◽  
Robert Perneczky ◽  
Na Zou ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Differential Diagnosis ◽  
Frontotemporal Lobar Degeneration ◽  
Elderly Subjects ◽  
Single Subject ◽  
Linear Discriminant ◽  
Healthy Elderly ◽  
Metabolic Connectivity ◽  
Dementing Disorders

Presently, visual and quantitative approaches for image-supported diagnosis of dementing disorders rely on regional intensity rather than on connectivity measurements. Here, we test metabolic connectivity for differentiation between Alzheimer’s disease and frontotemporal lobar degeneration. Positron emission tomography with 18F-fluorodeoxyglucose was conducted in 47 patients with mild Alzheimer’s disease, 52 patients with mild frontotemporal lobar degeneration, and 45 healthy elderly subjects. Sparse inverse covariance estimation and selection were used to identify patterns of metabolic, inter-subject covariance on the basis of 60 regional values. Relative to healthy subjects, significantly more pathological within-lobe connections were found in the parietal lobe of patients with Alzheimer’s disease, and in the frontal and temporal lobes of subjects with frontotemporal lobar degeneration. Relative to the frontotemporal lobar degeneration group, more pathological connections between the parietal and temporal lobe were found in the Alzheimer’s disease group. The obtained connectivity patterns differentiated between two patients groups with an overall accuracy of 83%. Linear discriminant analysis and univariate methods provided an accuracy of 74% and 69%, respectively. There are characteristic patterns of abnormal metabolic connectivity in mild Alzheimer’s disease and frontotemporal lobar degeneration. Such patterns can be utilized for single-subject analyses and might be more accurate in the differential diagnosis of dementing disorders than traditional intensity-based analyses.

Reproducibility of Brain Volume Changes in Longitudinal Voxel-Based Morphometry Between Non-Accelerated and Accelerated Magnetic Resonance Imaging

2021 ◽  
pp. 1-10
Author(s):  
Hidemasa Takao ◽  
Shiori Amemiya ◽  
Osamu Abe ◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Magnetic Resonance ◽  
Gray Matter ◽  
Gray Matter Volume ◽  
Elderly Subjects ◽  
Voxel Based Morphometry ◽  
Volume Changes ◽  
Matter Volume ◽  
Healthy Elderly

Background: Scan acceleration techniques, such as parallel imaging, can reduce scan times, but reliability is essential to implement these techniques in neuroimaging. Objective: To evaluate the reproducibility of the longitudinal changes in brain morphology determined by longitudinal voxel-based morphometry (VBM) between non-accelerated and accelerated magnetic resonance images (MRI) in normal aging, mild cognitive impairment (MCI), and Alzheimer’s disease (AD). Methods: Using data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) 2 database, comprising subjects who underwent non-accelerated and accelerated structural T1-weighted MRI at screening and at a 2-year follow-up on 3.0 T Philips scanners, we examined the reproducibility of longitudinal gray matter volume changes determined by longitudinal VBM processing between non-accelerated and accelerated imaging in 50 healthy elderly subjects, 54 MCI patients, and eight AD patients. Results: The intraclass correlation coefficient (ICC) maps differed among the three groups. The mean ICC was 0.72 overall (healthy elderly, 0.63; MCI, 0.75; AD, 0.63), and the ICC was good to excellent (0.6–1.0) for 81.4%of voxels (healthy elderly, 64.8%; MCI, 85.0%; AD, 65.0%). The differences in image quality (head motion) were not significant (Kruskal–Wallis test, p = 0.18) and the within-subject standard deviations of longitudinal gray matter volume changes were similar among the groups. Conclusion: The results indicate that the reproducibility of longitudinal gray matter volume changes determined by VBM between non-accelerated and accelerated MRI is good to excellent for many regions but may vary between diseases and regions.

scholarly journals Effect of cortisol levels on working memory performance in elderly subjects with Alzheimer's disease

2008 ◽  
Vol 66 (3b) ◽  
pp. 619-624 ◽  
Author(s):  
Juliana Nery de Souza-Talarico ◽  
Paulo Caramelli ◽  
Ricardo Nitrini ◽  
Eliane Corrêa Chaves
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Working Memory ◽  
Digit Span ◽  
Memory Performance ◽  
Elderly Subjects ◽  
Control Group ◽  
Acute Administration ◽  
Healthy Elderly ◽  
Cortisol Levels

BACKGROUND: Subjects with Alzheimer's disease (AD) have elevated cortisol levels as a result of hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Acute administration of hydrocortisone has been associated with working memory (WM) performance in young adults. OBJECTIVE: To investigate whether cortisol levels are associated with WM performance in subjects with AD. METHOD: Eighty subjects were included, comprising 40 patients with mild AD and 40 healthy elderly controls. WM was assessed using the Digit Span Backward test (DSB). Saliva samples were collected to determine cortisol levels. RESULTS: AD subjects had poorer performance on the DSB than controls (p=0.002) and also presented higher levels of cortisol than control group (p=0.04). No significant correlation was observed between the DSB and cortisol levels in both groups (r= -0.29). CONCLUSION: In this study, elevated cortisol levels were not associated with poorer WM performance in patients with AD or in healthy elderly subjects.

Impact of cognitive task on the posture of elderly subjects with Alzheimer's disease compared to healthy elderly subjects

2006 ◽  
Vol 21 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Patrick Manckoundia ◽  
Pierre Pfitzenmeyer ◽  
Philippe d'Athis ◽  
Véronique Dubost ◽  
France Mourey
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Task ◽  
Elderly Subjects ◽  
Healthy Elderly ◽  
Healthy Elderly Subjects

scholarly journals Lexical Retrieval or Semantic Knowledge Which One Causes Naming Errors in Patients with Mild and Moderate Alzheimer’s Disease

2017 ◽  
Vol 7 (3) ◽  
pp. 419-429 ◽  
Author(s):  
Masoome Salehi ◽  
Mohsen Reisi ◽  
Leila Ghasisin
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Healthy Subjects ◽  
Conceptual Knowledge ◽  
Semantic Knowledge ◽  
Elderly Subjects ◽  
Lexical Retrieval ◽  
Healthy Elderly ◽  
Written Word ◽  
Healthy Elderly Subjects

Background: The purpose of the study was to analyze naming errors in patients with Alz­heimer’s disease in comparison to healthy subjects and determine the underlying cause of naming errors in these patients. Method: In this study, we included 35 healthy elderly subjects, 23 patients with mild Alzheimer’s disease, and 23 with moderate Alzheimer’s disease. Forty-five images were used to determine the type of naming errors, and to identify the underlying cause of errors, matching an image with a written word was used. Results: Patients with Alz­heimer’s disease had more naming errors compared with the group of healthy elderly, and patients with moderate Alzheimer’s disease showed a slower reaction in matching an image with a written word. Conclusion: Anomia in the initial phase of Alzheimer’s disease is due to problems in lexical retrieval; however, as the disease advances, in addition to lexical retrieval problems, conceptual knowledge causes naming problems.

scholarly journals Behavioral and activities of daily living inventories in the diagnosis of frontotemporal lobar degeneration and Alzheimer's disease

2008 ◽  
Vol 2 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Valéria Santoro Bahia ◽  
Mari-Nilva Maia da Silva ◽  
Rene Viana ◽  
Jerusa Smid ◽  
Antonio Eduardo Damin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Differential Diagnosis ◽  
Activities Of Daily Living ◽  
Frontotemporal Lobar Degeneration ◽  
Daily Living ◽  
Qualitative Assessment ◽  
Functional Deficits ◽  
Brazilian Version ◽  
Severity Of The Disease

Abstract The differential diagnosis between frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD) is often challenging. Objectives: To verify the usefulness of behavioral and activities of daily living inventories in the differential diagnosis between FTLD and AD. Methods: Caregivers of 12 patients with FTLD (nine with frontotemporal dementia, two with semantic dementia and one with progressive non-fluent aphasia) and of 12 patients with probable AD were interviewed. The Brazilian version of the Frontal Behavioral Inventory (FBI) and Disability Assessment for Dementia (DAD ) were used. Results: The mean of the MMSE score was 12.4±10.7 for patients with FTLD and 11.9±6.2 for patients with AD (p=0.93). Mean scores on the DAD were 33.7±27.7 in patients with FTLD and 55.6±29.7 in patients with AD (p=0.06), while for the FBI they were 42.6±10.0 for FTLD and 16.7±11.7 for AD (p<0.01). Conclusions: In this study, FBI was found to be a helpful tool for the differential diagnosis between FTLD and AD. Although the DAD was not useful in differential diagnosis in our sample we believe it to be important for measuring the severity of the disease through quantitative and qualitative assessment of functional deficits of the patients.

scholarly journals The Acetylcholine Index: An Electroencephalographic Marker of Cholinergic Activity in the Living Human Brain Applied to Alzheimer's Disease and Other Dementias

2014 ◽  
Vol 39 (3-4) ◽  
pp. 132-142 ◽  
Author(s):  
Magnus Johannsson ◽  
Jon Snaedal ◽  
Gisli Holmar Johannesson ◽  
Thorkell Eli Gudmundsson ◽  
Kristinn Johnsen
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Human Brain ◽  
Elderly Subjects ◽  
Cholinergic Activity ◽  
Healthy Elderly ◽  
Age Related ◽  
General Decline ◽  
Using Data

Background: The cholinergic hypothesis is well established and has led to the development of pharmacological treatments for Alzheimer's disease (AD). However, there has previously been no physiological means of monitoring cholinergic activity in vivo. Methods: An electroencephalography (EEG)-based acetylcholine (Ach) index reflecting the cholinergic activity in the brain was developed using data from a scopolamine challenge study. The applicability of the Ach index was examined in an elderly population of healthy controls and patients suffering from various causes of cognitive decline. Results: The Ach index showed a strong reduction in the severe stages of AD dementia. A high correlation was demonstrated between the Ach index and cognitive function. The index was reduced in patients with mild cognitive impairment and prodromal AD, indicating a decreased cholinergic activity. When considering the distribution of the Ach index in a population of healthy elderly subjects, an age-related threshold was revealed, beyond which there is a general decline in cholinergic activity. Conclusions: The EEG-based Ach index provides, for the first time, a physiological means of monitoring the cholinergic activity in the human brain in vivo. This has great potential for aiding diagnosis and patient stratification as well as for monitoring disease progression and treatment response. © 2014 S. Karger AG, Basel

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